272 Isospondyli 
large, brilliantly silvery, toothless fishes, looking like enormous 
dace, swift in the water, and very abundant in the Gulf of 
Fig. 204.—Milkfish, Chanos chanos (L.). Mazatlan. 
California, Polynesia, and India. The single living species is 
the Awa, or milkfish, Chanos chanos, largely used as food 
in Hawaii. Species of Prochanos and Chanos occur in the 
Cretaceous, Eocene, and Miocene. Allied to Chanos is the 
Cretaceous genus Ancylostylos (gibbus), probably the type of 
a distinct family, toothless and with many-rayed dorsal. 
The Hiodontide.—The Hiodontide, or mooneyes, inhabit the 
rivers of the central portion of the United States and Canada. 
Fig. 205.—Mooneye, Hiodon tergisus Le Sueur. Ecorse, Mich. 
They are shad-like fishes with brilliantly silvery scales and very 
strong sharp teeth, those on the tongue especially long. They are 
very handsome fishes and take the hook with spirit, but the 
flesh is rather tasteless and full of small bones, much like that 
